Here is a smart health tracking wearable that uses solar power and your body heat to keep going. It offers 24/7 activity tracking. The Mother Bracelet comes with a temperature sensor, accelerometer, gyroscope, and PPG heart rate sensor. It also has a LED and vibration motor. It is water resistant to 50m.
This gadget combines with your phone to track number of steps taken, sleep quality, heart rate, body temperature, and calories consumed. It weighs only 0.066lb, so you can wear it around comfortably.